<template>
  <div class='sub-sort'>
    <div class="sort">
      <a :class="{active:sortParams.sortField===null}" @click="changeSort(null)" href="javascript:;">默认排序</a>  
      <a :class="{active:sortParams.sortField==='publishTime'}" @click="changeSort('publishTime')" href="javascript:;">最新商品</a>
      <a :class="{active:sortParams.sortField==='orderNum'}" @click="changeSort('orderNum')" href="javascript:;">最高人气</a>
      <a :class="{active:sortParams.sortField==='evaluateNum'}" @click="changeSort('evaluateNum')" href="javascript:;">评论最多</a>
      <a  @click="changeSort('price')" href="javascript:;">
        价格排序
        <i class="arrow up" :class="{active:sortParams.sortField==='price'&&sortParams.sortMethod==='asc'}"/>
        <i class="arrow down" :class="{active:sortParams.sortField==='price'&&sortParams.sortMethod==='desc'}"/>
      </a>
    </div>
    <div class="check">
      <XtxCheckbox @click="changeBox" v-model="sortParams.inventory">仅显示有货商品</XtxCheckbox>
      <XtxCheckbox @click="changeBox" v-model="sortParams.onlyDiscount">仅显示特惠商品</XtxCheckbox>
    </div>
  </div>
</template>
<script>
import { reactive } from 'vue'
export default {
  name: 'SubSort',
  setup(props,{emit}){
    // 1.根据后台需要的参数定义数据对象
    // 2.根据数据对象 绑定组件
    // 3.在操作组件的时候需要反馈给数据对象
     let sortParams = reactive({
      inventory: false,//是否有库存
      onlyDiscount: false,//只显示特惠
      sortField: null,//排序字段，取值范围：[publishTime,orderNum,price,evaluateNum]
      sortMethod: null //排序规则，asc为正序，desc为倒序，默认为desc
    })

    // 改变排序
    const changeSort=(sortField)=>{
      if(sortField==='price'){
        sortParams.sortField=sortField
        if(sortParams.sortField===null){
          // 第一次点击价格排序 默认时降序
          sortParams.sortMethod='desc'
        }else{
          // 其他情况 取反
          sortParams.sortMethod=sortParams.sortMethod==='desc'?'asc':'desc'
        }
      }else{
        // console.log('1',sortField);   
        // 如果排序未改变 则停止逻辑
        if(sortParams.sortField===sortField) return
        sortParams.sortField=sortField
        sortParams.sortMethod=null
      }
      // 触发自动以事件，将筛选条件数据传到sub组件
      emit('sort-change', sortParams)
    }

    const changeBox=(sortParams)=>{
      // 触发自动以事件，将筛选条件数据传到sub组件
      emit('sort-change', sortParams)
    }

    return {sortParams,changeSort,changeBox}
  }

}
</script>
<style scoped lang='less'>
@import '~@/assets/styles/variables.less';
.sub-sort {
  height: 80px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  .sort {
    display: flex;
    a {
      height: 30px;
      line-height: 28px;
      border: 1px solid #e4e4e4;
      padding: 0 20px;
      margin-right: 20px;
      color: #999;
      border-radius: 2px;
      position: relative;
      transition: all .3s;
      &.active {
        background: @xtxColor;
        border-color: @xtxColor;
        color: #fff;
      }
      .arrow {
        position: absolute;
        border: 5px solid transparent;
        right: 8px;
        &.up {
          top: 3px;
          border-bottom-color: #bbb;
            &.active {
            border-bottom-color: @xtxColor;
          }
        }
        &.down {
          top: 15px;
          border-top-color: #bbb;
          &.active {
            border-top-color: @xtxColor;
          }
        }
      }
    }
  }
  .check {
    .xtx-checkbox {
      margin-left: 20px;
      color: #999;
    }
  }
}
</style>